Elevator power generation braking intelligent device, including its traction drive elevator

Abstract

The present invention relates to the fields of industrial automatic control system device manufacturing, intelligent basic general equipment, AI + construction, etc. in the high-end equipment manufacturing industry, and particularly relates to an intelligent elevator power generation braking device, including a traction-driven elevator thereof. The intelligent elevator power generation braking device of the present invention includes: an excitation module and a power load module; a main control circuit, which is used to control the access switch group to connect the excitation module and the power load module to a three-phase asynchronous motor when an out-of-control state of the elevator is detected, and the excitation module provides excitation current for the three-phase asynchronous motor; the rotor of the three-phase asynchronous motor rotates due to the out-of-control of the elevator, and the three-phase asynchronous motor enters a power generation state and outputs electric energy outward; the power load module consumes electric energy and generates a braking torque on the out-of-control elevator. The present invention utilizes the principle of asynchronous power generation of a three-phase asynchronous motor and limits the speed of the motor by controlling the consumption of the electric energy output by the motor, providing a novel elevator braking method.

Description

Technical Field

[0001] The present invention relates to the fields of industrial automatic control system device manufacturing, intelligent basic general equipment, AI + architecture, etc. in the high-end equipment manufacturing industry, and particularly relates to an intelligent elevator power generation braking device, including a traction-driven elevator thereof. Background Art

[0002] With the construction of high-rise buildings in China, elevators have been widely used. Among them, traction-driven elevators are the most widely used.

[0003] Figure 1 As shown in the structural schematic diagram of the prior art traction-driven elevator. Figure 1 As shown, the traction rope 4 is wound around the traction wheel, and the traction wheel is driven by the motor 1. The first end of the traction rope is suspended through the rope socket assembly 6 to carry the passenger car 7, and the second end of the traction rope 4 is suspended through the guide wheel 5 to carry the counterweight device 8. When the motor 1 starts, the torque output by it is converted into a preset speed through the reducer 3, driving the traction wheel to rotate; the friction between the traction wheel and the traction rope 4 generates traction force, so that the car and the counterweight move relatively, that is, the car rises and the counterweight descends; the counterweight rises and the car descends. Usually, under the no-load state, the counterweight is 40% to 50% of the rated load heavier than the no-load car. For example, for an elevator with a rated load of 1000 kg, the counterweight is 400 to 500 kg heavier than the car when the car is no-load. In order to ensure the safe operation of the elevator and prevent the uncontrolled movement of the motor, a brake 2 is provided in the traction-driven elevator.

[0004] However, in continuous production practice, the applicant has found that: the brake, especially the brake on old elevators, is an isolated device with poor reliability. In the case of brake failure, the mass difference between the no-load car and the counterweight will cause the car to accelerate upward, and the mass difference between the full-load car and the counterweight will cause the car to accelerate downward, ultimately hitting the end of the hoistway at high speed and causing serious losses, and the victims will either die or be injured. Summary of the Invention

[0005] I. Technical Problems to be Solved

[0006] The present invention expects to solve at least one of the above technical problems.

[0007] II. Technical Solutions

[0008] In the first aspect of the present invention, an intelligent elevator power generation braking device is provided, including: an excitation module and a power load module; a state monitoring module for monitoring the operating state of the elevator; an access switch group connected between the excitation module, the power load module and the three-phase terminals of the three-phase asynchronous motor; a main control circuit for controlling the access switch group to connect both the excitation module and the power load module to the three-phase asynchronous motor when an out-of-control state of the elevator is detected, where: the excitation module provides an excitation current for the three-phase asynchronous motor; the rotor of the three-phase asynchronous motor rotates due to the out-of-control of the elevator, and the three-phase asynchronous motor enters a power generation state and outputs electric energy outward; the power load module consumes electric energy, thereby generating a braking torque on the out-of-control elevator.

[0009] In some embodiments of the present invention, the excitation module includes: N capacitors, N≥2; wherein, one or more of the N capacitors form an energy storage and energy release excitation unit between the two ends of the three-phase terminals of the three-phase asynchronous motor.

[0010] In some embodiments of the present invention, the excitation module includes: a first capacitor, a second capacitor, and a third capacitor, where: the first capacitor is connected between the A terminal and the B terminal of the three-phase asynchronous motor; the second capacitor is connected between the B terminal and the C terminal of the three-phase asynchronous motor; the third capacitor is connected between the A terminal and the C terminal of the three-phase asynchronous motor; wherein, the capacitance values of the first capacitor, the second capacitor, and the third capacitor are the same or different.

[0011] In some embodiments of the present invention, the three-phase asynchronous motor is a power frequency motor, and the capacitance values C of the first capacitor, the second capacitor, and the third capacitor satisfy: , where the unit of the capacitance value C is μF, are the rated current, rated voltage, and power factor of the three-phase asynchronous motor respectively, and K is a coefficient, 500≤K≤10000.

[0012] In some embodiments of the present invention, the three-phase asynchronous motor is a non-power frequency motor, and the capacitance values C of the first capacitor, the second capacitor, and the third capacitor satisfy: , where: the unit of the capacitance value C is μF, are the rated current, rated voltage, and rated frequency of the three-phase asynchronous motor respectively, and Q is a coefficient, 0.1≤Q≤1.

[0013] In some embodiments of the present invention, the withstand voltages of the first capacitor, the second capacitor, and the third capacitor are not less than 110% of the rated voltage of the three-phase asynchronous motor.

[0014] In some embodiments of the present invention, the three-phase asynchronous motor is a power frequency motor with an operating frequency of 50 Hz. The capacitance values C of the first capacitor, the second capacitor, and the third capacitor are the same, and 3000 ≤ K ≤ 3500; or, the three-phase asynchronous motor is a non-power frequency motor, and the capacitance values C of the first capacitor, the second capacitor, and the third capacitor are the same, and 0.2 ≤ Q ≤ 0.4.

[0015] In some embodiments of the present invention, the excitation module includes: a fifth capacitor, a sixth capacitor, and a seventh capacitor, where: the fifth capacitor and the sixth capacitor are connected between the A terminal and the B terminal of the three-phase asynchronous motor; the sixth capacitor and the seventh capacitor are connected between the B terminal and the C terminal of the three-phase asynchronous motor; the seventh capacitor and the fifth capacitor are connected between the C terminal and the A terminal of the three-phase asynchronous motor; among them, the capacitance values of the fifth capacitor, the sixth capacitor, and the seventh capacitor may be the same or different.

[0016] In some embodiments of the present invention, the capacitance values C of the fifth capacitor, the sixth capacitor, and the seventh capacitor satisfy: , where are the rated current, rated voltage, and power factor of the three-phase asynchronous motor respectively, S is a coefficient, and 500 ≤ S ≤ 3000.

[0017] In some embodiments of the present invention, the power load module includes: M impedance elements, M ≥ 1; among them, at least one of the three positions between the two terminals of the three-phase asynchronous motor forms a power load by one or more of the M impedance elements.

[0018] In some embodiments of the present invention, it further includes: a load switch group, and the load switch group includes: a first load switch and a second load switch; the power load module includes: a first resistor, a second resistor, and a third resistor, where: the first resistor and the third resistor are connected between the A terminal and the B terminal of the three-phase asynchronous motor through the first load switch; the third resistor and the second resistor are connected between the B terminal and the C terminal of the three-phase asynchronous motor through the second load switch; the second resistor and the first resistor are connected between the C terminal and the A terminal of the three-phase asynchronous motor through the first load switch and the second load switch.

[0019] In some embodiments of the present invention, the main control circuit is further configured to: when detecting an out-of-control state of the elevator, set the first load switch and the second load switch to the closed state; when detecting that the rotational speed of the three-phase asynchronous motor drops to a preset first rotational speed lower limit value, make at least one of the first load switch and the second load switch in the open state; where the first rotational speed lower limit value is n down-1 satisfies: n down-1 ≤ 0.8n0, where n0 is the rated rotational speed of the three-phase asynchronous motor.

[0020] In some embodiments of the present invention, the first load switch and the second load switch are: a relay or a transistor chopper; and / or, the resistance values of the first resistor, the second resistor, and the third resistor are the same or different; and / or, the resistance values R of the first resistor, the second resistor, and the third resistor satisfy: , where the unit of the resistance value R is ohm, is the rated voltage of the three-phase asynchronous motor, is the input power of the motor when the elevator is running empty, and 0.5 ≤ T ≤ 2.

[0021] In some embodiments of the present invention, the resistance values of the first resistor, the second resistor, and the third resistor are the same; the resistance values R of the first resistor, the second resistor, and the third resistor satisfy: .

[0022] In some embodiments of the present invention, the power load module includes: a full-wave rectifier circuit; a chopper, a chopper control module, and a load resistor; wherein, the full-wave rectifier circuit full-wave rectifies three-phase alternating current into direct current, and the direct current is connected to the load resistor through the chopper, and the load current is continuously adjusted by adjusting the chopping voltage of the chopper, thereby controlling the braking torque.

[0023] In some embodiments of the present invention, it further includes: an asynchronous power generation start auxiliary module for outputting excitation pulses to the three-phase asynchronous motor; an access switch group connected between any two of the three-phase terminals of the asynchronous power generation start auxiliary module and the three-phase asynchronous motor; a main control circuit for: when it is monitored that the speed of the three-phase asynchronous motor is higher than a preset second speed lower limit value, if no output voltage of the three-phase asynchronous motor is detected, the main control circuit outputs excitation pulses to the three-phase asynchronous motor through the asynchronous power generation start auxiliary module to make the motor enter the asynchronous power generation state; wherein, the second speed lower limit value is between 50% and 90% of the rated speed of the three-phase asynchronous motor.

[0024] In some embodiments of the present invention, the asynchronous power generation start auxiliary module includes: a DC power supply, the negative output terminal of which is connected to one of the three terminals of the three-phase asynchronous motor; a switch component, the first end of which is connected to the positive output terminal of the DC power supply, and the second end of which is connected to another one of the three terminals of the three-phase asynchronous motor.

[0025] In some embodiments of the present invention, the asynchronous power generation start auxiliary module further includes: a diode, the negative extreme of which is connected to the second end of the switch component, and the positive extreme of which is connected to another one of the three terminals of the three-phase asynchronous motor; and / or, the frequency of the excitation pulse f satisfies: 0.5 kHz ≤ f≤5 kHz; and / or, the output voltage of the DC power supply is between 10 V and 36 V; and / or, the switching component is an Insulated Gate Bipolar Transistor (IGBT).

[0026] In some embodiments of the present invention, a state monitoring module is configured to monitor the active power input and the rotation of the rotor in the elevator; a main control circuit is configured to determine that the elevator is in an out-of-control state when the following conditions are met: the three-phase asynchronous motor rotates without active power input; and execute the following control logic according to the determination result: when the out-of-control state of the elevator is not detected, keep the connection terminals of both the excitation module and the power load module connected to the three-phase asynchronous motor and the elevator control cabinet isolated; when the out-of-control state of the elevator is detected, control the access switch group to connect both the excitation module and the power load module in parallel to the connection terminals of the three-phase asynchronous motor and the elevator control cabinet.

[0027] In some embodiments of the present invention, the state monitoring module includes: a motor power monitoring module configured to monitor the power voltage input to the three-phase asynchronous motor; a motor rotation monitoring module configured to monitor the rotation of the rotor in the three-phase asynchronous motor.

[0028] In some embodiments of the present invention, the motor rotation monitoring module is: a magnetic encoder, which is disposed at the shaft end of the three-phase asynchronous motor, and the shaft end is connected to the rotor, and its sampling period T satisfies: T ≤ 20 ms; and / or, the motor current detection module is a voltage transmitter.

[0029] The second aspect of the present invention provides a traction-driven elevator, including: a car; a traction wheel driven by a three-phase asynchronous motor; a traction rope, the middle part of which passes around the traction wheel, the first end is connected to the car; the second end is connected to a counterweight device; the elevator power generation braking intelligent device as described above; an upper buffer and a lower buffer, which are respectively disposed at the upper end and the lower end of the elevator shaft; wherein, when it is detected that the elevator is in an out-of-control state, the three-phase asynchronous motor enters a power generation state, and the power load module is used as an output load to consume the electric energy output by the three-phase asynchronous motor, generate a braking torque, and slow down the movement speed of the elevator car.

[0030] III. Beneficial Effects

[0031] From the above technical solutions, the present invention has at least one of the following beneficial effects compared with the prior art:

[0032] 1. The present invention utilizes the principle of asynchronous power generation of a three-phase asynchronous motor, and limits the rotation speed of the motor by controlling the consumption of the electric energy output by the motor, thereby limiting the out-of-control moving speed of the elevator, making the entire out-of-control moving speed not exceed the rated operating speed, ensuring that the braking deceleration does not exceed the preset speed, and avoiding serious personal injuries or property losses, thus providing a novel elevator braking method.

[0033] 2. In the present invention, there is usually residual magnetism in the rotor of a three-phase asynchronous motor. During the rotation of the rotor, an induced current is generated in the stator coil to charge the first capacitor C1, the second capacitor C2, and the third capacitor C3. The voltage across the three capacitors lags the current by 90°. The three capacitors discharge through the stator coil to provide the excitation current, and the motor enters the power generation state.

[0034] In some embodiments of the present invention, excitation by means of capacitors can achieve automatic control of charging / discharging, reduce other interventions, and ensure the reliable start of the elevator power generation braking intelligent device.

[0035] 3. In the present invention, the capacitance values of the first capacitor, the second capacitor, and the third capacitor are the same, which can ensure that the three-phase output powers are the same in the power generation state of the three-phase asynchronous motor, thereby making the reliability of the entire circuit higher.

[0036] 4. In the present invention, when the elevator power generation braking intelligent device enters the power generation state and the magnetic encoder monitors that the rotor speed is close to the rated speed, the main control electric control controls the relays K1 and K2 to close, connects the three load resistors -R1, R2, and R3, and starts to consume the electric energy output by the three-phase asynchronous motor to generate a braking torque.

[0037] Furthermore, when it is found that the speed of the three-phase asynchronous motor drops to 80%, in order to avoid the collapse of the power generation state due to too low speed, according to the speed drop situation, K1 and K2 are selected to be disconnected or K1 and K2 are disconnected simultaneously to change the load situation, adjust the braking torque, and achieve continuously adjustable electric energy consumption control, so as to more precisely control the braking torque.

[0038] 5. In the asynchronous power generation start auxiliary module of the present invention, a pulse similar to the rotor rotation speed is passed through a DC power supply into the three-phase asynchronous motor for one cycle to magnetize the rotor. After magnetization, the three-phase asynchronous motor can enter a power generation state, ensuring the smooth start of the power generation state.

[0039] 6. The differences compared with the specific prior art and the beneficial effects produced

[0040] (1) CN116891173A

[0041] CN116891173A provides an elevator and its control method, including a car; a traction machine connected to the car; a drive system including a motor that drives the rotation of the traction machine through a transmission shaft; a monitoring system for monitoring the rotational speed of the transmission shaft and the alternating current supply current of the motor; and a speed control system that controls the drive system to reduce the rotational speed when the alternating current supply current is lower than a predetermined first current threshold and the rotational speed is higher than a predetermined speed threshold. When the drive system gets out of control, the monitoring system, drive system, and speed control system of the elevator can cooperate with each other to monitor and control the drive system to reduce the rotational speed of the transmission shaft, so that the traction machine drives the car to rise or fall at a low speed, preventing the passengers in the car from being injured.

[0042] Compared with CN116891173A, the intelligent device for elevator power generation braking of the present invention has the following advantages: ① DC braking requires continuous power supply and cannot achieve continuous braking without power supply, while the power generation braking of the present invention can be achieved by the self-excitation power generation of the motor, relying less on the power supply. In necessary cases, the power supply of the main control circuit can rely on the power generation of the asynchronous motor; ② DC braking requires a large braking current for braking at the rated speed or even overspeed, and such power supply may not be available in many cases. However, the asynchronous power generation braking of the present invention can generate braking torque with a very low power supply. After the power generation state is established, the power supply of the device itself can be supplied by the electric energy generated by the asynchronous motor, getting rid of the dependence on external power supply.

[0043] (2)US5070290A

[0044] In US5070290A, when the power supply is suddenly interrupted during the normal operation of the elevator, the control system will control the frequency converter to make the elevator enter the deceleration state, and use the power generation state when the frequency converter outputs negative torque to supply power to the control system, frequency converter, and brake for a short time. When the power supply is restored, the elevator returns to the normal operation state. However, if the power supply still has not been restored after exceeding the specified time, the power supply of the brake is cut off to brake the elevator. In this state, the process of the previous frequency converter relying on the negative torque output for power generation to maintain the deceleration operation of the elevator will significantly reduce the running speed of the elevator, and can effectively reduce the burden on the mechanical brake when the mechanical brake intervenes in braking.

[0045] The present invention is applied to the state where the asynchronous motor loses the drive of the frequency converter and the mechanical brake fails. The excitation current is established through the residual magnetism power generation of the motor or through pulse excitation, and the asynchronous power generation state of the asynchronous motor is used to limit the maximum running speed of the elevator without the control of the frequency converter, so that the elevator stops relatively safely under the action of the buffer, avoiding serious consequences caused by the speed of the elevator car or counterweight exceeding the design parameters of the buffer when contacting the buffer.

[0046] (3)CN102712442A

[0047] CN102712442A is only applicable to synchronous motors, and utilizes the synchronous power generation principle of the stator coils of synchronous motors cutting the magnetic field of the rotor permanent magnets for energy consumption braking.

[0048] However, the motor applicable to the present invention is an asynchronous motor. There is no permanent magnet in the motor, and it is necessary to utilize the externally provided exciting current to enter the asynchronous power generation state for energy consumption braking.

[0049] (4)CN103508286A

[0050] In CN103508286A, asynchronous electric excitation is adopted. The capacitor is installed between the three-phase rectifier bridge and the three-phase fully controlled bridge for inversion. Its function is to filter the direct current after the three-phase alternating current is rectified. And for exciting the three-phase asynchronous motor, electric excitation is adopted. The three-phase fully controlled bridge, driven by the control system, inverses the direct current into three-phase alternating current. When the rotor speed of the motor driven by external power is higher than the rotational speed of the exciting magnetic field, it enters the asynchronous power generation state.

[0051] However, the present invention adopts capacitive reactance excitation. The three exciting capacitors are directly connected to the power supply terminals of the asynchronous motor. Utilizing the characteristics that the capacitor current leads in phase and the voltage lags in phase, it automatically adjusts the rotational speed of the rotating magnetic field of the exciting magnetic field as the motor speed changes, so that the rotation of the exciting magnetic field always lags behind the rotor of the motor and thus enters the asynchronous power generation state, which is fundamentally different from the excitation principle of CN103508286A. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 FIG. is a schematic structural diagram of a traction drive elevator in the prior art.

[0053] Figure 2 FIG. is a schematic structural diagram of the elevator power generation braking intelligent device according to the first embodiment of the present invention.

[0054] Figure 3 For Figure 2 FIG. is a schematic diagram of the delta connection of capacitors in the excitation module of the elevator power generation braking intelligent device shown.

[0055] Figure 4 FIG. is a schematic structural diagram of the elevator power generation braking intelligent device according to the second embodiment of the present invention.

[0056] Figure 5 For Figure 4 FIG. is a schematic diagram of the star connection of capacitors in the elevator power generation braking intelligent device shown.

[0057] Figure 6 FIG. is a schematic structural diagram of the elevator power generation braking intelligent device according to the third embodiment of the present invention. Detailed implementation mode

[0058] The present invention utilizes the principle of asynchronous power generation of a three-phase asynchronous motor, and limits the rotational speed of the motor by controlling the consumption of the electric energy output by the motor, thereby limiting the out-of-control moving speed of the elevator, making the entire out-of-control moving speed not exceed the rated operating speed, ensuring that the braking deceleration does not exceed the preset speed, and avoiding causing serious personal injuries or property losses, thereby providing a novel elevator braking method.

[0059] To make the purpose, technical solution and advantages of the present invention clearer and more understandable, the following further details the present invention in combination with specific implementation modes and with reference to the accompanying drawings.

[0060] The first embodiment of the present invention provides an intelligent device for elevator power generation braking. Figure 2 It is a structural schematic diagram of the intelligent device for elevator power generation braking according to the first embodiment of the present invention. As Figure 2 shown, the intelligent device for elevator power generation braking in this embodiment includes:

[0061] An excitation module and a power load module;

[0062] A state monitoring module for monitoring the operating state of the elevator;

[0063] An asynchronous power generation start auxiliary module for outputting excitation pulses to the three-phase asynchronous motor;

[0064] An access switch group connected between the three-phase terminals of the excitation module, the power load module, the asynchronous power generation start auxiliary module and the three-phase asynchronous motor;

[0065] A main control circuit for judging the out-of-control state of the elevator, and when the out-of-control state of the elevator is judged, controlling the access switch group to connect the excitation module and the power load module to the three-phase asynchronous motor, wherein:

[0066] The excitation module provides excitation current for the three-phase asynchronous motor;

[0067] The rotor of the three-phase asynchronous motor rotates due to the out-of-control of the elevator, and the three-phase asynchronous motor enters the power generation state and outputs electric energy outward;

[0068] The power load module consumes the electric energy, thereby generating a braking torque on the out-of-control elevator.

[0069] In this embodiment, the asynchronous power generation start auxiliary module is provided to ensure the smooth start of the power generation state, and can be omitted in some embodiments of the present invention. In addition, in other embodiments of the present invention, the state monitoring module may no longer be provided separately, but share the state monitoring module of other systems in the elevator. Such two deformation methods can also achieve the present invention and are also within the protection scope of the present invention.

[0070] The following will describe in detail each component of the elevator power generation braking intelligent device of this embodiment.

[0071] In this embodiment, the status monitoring module is used to monitor the active power input and the rotation of the rotor in the elevator, so as to judge the operating status of the elevator. Specifically, the status monitoring module includes: a motor power monitoring module, which is used to monitor the power voltage input to the three-phase asynchronous motor; a motor rotation monitoring module, which is used to monitor the rotation of the rotor in the three-phase asynchronous motor.

[0072] As Figure 2 shown, the motor rotation monitoring module is: a magnetic encoder, which is arranged at the shaft end of the three-phase asynchronous motor, and this shaft end is connected to the rotor, and its sampling period T satisfies: T ≤ 20 ms; the motor current detection module is a voltage transmitter to monitor the power voltage.

[0073] The main control circuit is used to judge that the elevator is in an out-of-control state when the following conditions are met: the three-phase asynchronous motor rotates without active power input. Based on the judgment, the main control circuit makes the following logical actions:

[0074] ① When the out-of-control state of the elevator is not detected, keep the connection terminals of both the excitation module and the power load module connected to the three-phase asynchronous motor and the elevator control cabinet isolated;

[0075] ② When the out-of-control state of the elevator is detected, control the access switch group to connect both the excitation module and the power load module in parallel to the connection terminals of the three-phase asynchronous motor and the elevator control cabinet.

[0076] In the prior art, when it is detected that the motor of the elevator runs at more than 115% of the rated speed, the built-in braking device of the elevator will intervene. However, under normal circumstances, at this time, the elevator has already moved several meters or even farther. During this period, the elevator door is definitely not closed. If there is a person standing with one foot inside and one foot outside the elevator door during this period, or if a person falls in this interval, then this person will be sheared between the car and the landing sill of the landing door, resulting in a very tragic accident scene.

[0077] In this embodiment, a state monitoring module and a main control circuit are provided. When it is found that the rotor of the motor rotates and there is no current in the motor coil, and the voltage across the coil ends does not reach the voltage corresponding to this rotational speed, it is determined that the elevator has an unexpected movement. Experiments have shown that due to the use of a magnetic encoder, when the moving speed of the car reaches 80% of the rated speed within 20 ms, the elevator power generation braking device in this embodiment will quickly respond, and then make the elevator enter the power generation braking operation state, restricting the moving speed of the elevator not to exceed the rated rotational speed. Finally, when the elevator car squats on the buffers at the bottom or top of the elevator shaft, the speed at which the elevator impacts the buffer can meet the design requirements of the elevator buffer, ensuring the personal safety of passengers.

[0078] In this embodiment, two parameters, namely active power input and rotor rotation, are used to judge the operating state of the three-phase asynchronous motor, but the present invention is not limited thereto. Those skilled in the art should understand that the operating state of the three-phase asynchronous motor can also be monitored by other methods and other parameters, or the state monitoring components of other systems can be shared by the elevator power generation braking intelligent device of the present invention, and the present invention can be realized, and all are within the protection scope of the present invention.

[0079] As described above, during the normal operation of the elevator, the excitation module, the power load module, and the asynchronous power generation start auxiliary module are disconnected from the three-phase asynchronous motor; during the out-of-control of the elevator, the excitation module, the power load module, and the asynchronous power generation start auxiliary module are connected to the three-phase asynchronous motor. The "disconnection" and "connection" here are realized by an access switch group controlled by the main control circuit.

[0080] As Figure 2 shown, in this embodiment, the access switch group includes: a first switch, a second switch, and a third switch, which are respectively connected to the A terminal, the B terminal, and the C terminal of the three-phase asynchronous motor. These three switches are linked and open or close simultaneously.

[0081] Those skilled in the art should understand that the above structure is only an example, and the access switch group in the present invention can adopt any structure that can realize the controlled connection of the three-phase terminals of the three-phase asynchronous motor, and the present invention can be realized, and all are within the protection scope of the present invention.

[0082] To facilitate the understanding of the power generation process of the elevator power generation braking intelligent device in this embodiment, the interaction between the electromagnetic field generated by the stator and the electromagnetic field generated by the rotor in the three-phase asynchronous motor will be described below. Specifically, after the stator is energized with an excitation current, a magnetic field is generated. Due to the out-of-control of the elevator, the rotor rotates, and the rotor coil cuts this magnetic field, which will generate a current in the closed loop, and a rotating magnetic field will be generated as the rotor rotates. The stator coil cuts the rotating magnetic field to generate electricity.

[0083] In the present invention, the excitation module is used to provide excitation current to the three-phase asynchronous motor of the elevator. The excitation module has two forms:

[0084] ① The excitation module is implemented by capacitors

[0085] Specifically, the excitation module includes: N capacitors, N≥2, where one or more of the N capacitors form an energy storage and discharge excitation unit between the two terminals of the three terminals of the three-phase asynchronous motor. This implementation form will be described in detail in this embodiment.

[0086] ② The excitation module is implemented by a frequency converter

[0087] Figure 3 For Figure 2 is a schematic diagram of the capacitor delta connection in the excitation module of the elevator power generation braking intelligent device shown. As Figure 2 and Figure 3 shown, the excitation module includes: a first capacitor C1, a second capacitor C2, and a third capacitor C3, where: the first capacitor C1 is connected between the A terminal and the B terminal of the three-phase asynchronous motor; the second capacitor C2 is connected between the B terminal and the C terminal of the three-phase asynchronous motor; the third capacitor C3 is connected between the A terminal and the C terminal of the three-phase asynchronous motor. Among them, the withstand voltage of the three capacitors should not be less than 118% of the rated voltage of the three-phase asynchronous motor.

[0088] Theoretically speaking, the capacitance values of the first capacitor C1, the second capacitor C2, and the third capacitor C3 are related to the power generation amount and can be flexibly set within a certain range, but they cannot be too small or too large. The reasons are as follows:

[0089] ① If the capacitance is set too small, the current causing power generation collapse will be very small. For example: for an 11kW motor, if the capacitance value is selected reasonably, the motor can output about 8kW of power, but if the capacitance is too small, power generation may collapse at 3kW or 5kW.

[0090] ② If the capacitance is set too large, the capacitance itself will become a load of the alternating current, which will affect the efficiency of this embodiment and may also affect the function realization of other components.

[0091] It should be noted that for the two cases of the three-phase asynchronous motor being a power frequency motor and a non-power frequency motor, the conditions satisfied by the first to third capacitors are different, and the following will be described separately.

[0092] ① The three-phase asynchronous motor is a power frequency motor (operating frequency is 50Hz)

[0093] The capacitance values C of the first capacitor C1, the second capacitor C2, and the third capacitor C3 satisfy:

[0094]

[0095] Among them, the unit of the capacitance value C is μF. They are respectively the rated current, rated voltage, and power factor of the three-phase asynchronous motor, K is a coefficient, and 500 ≤ K ≤ 10000.

[0096] Preferably, 1000 ≤ K ≤ 2000. Most preferably, the capacitance values C of the first capacitor, the second capacitor, and the third capacitor are the same, and 3000 ≤ K ≤ 3500.

[0097] ② The three-phase asynchronous motor is a non-power frequency motor (the operating frequency is not 50 Hz).

[0098] The capacitance values C of the first capacitor C1, the second capacitor C2, and the third capacitor C3 satisfy:

[0099]

[0100] Among them: the unit of the capacitance value C is μF. They are respectively the rated current, rated voltage, and rated frequency of the three-phase asynchronous motor, Q is a coefficient, and 0.1 ≤ Q ≤ 1.

[0101] Preferably, 0.5 ≤ Q ≤ 1. Most preferably, the capacitance values C of the first capacitor, the second capacitor, and the third capacitor are the same, and 0.2 ≤ Q ≤ 0.4.

[0102] In this embodiment, usually, there is residual magnetism in the rotor of the three-phase asynchronous motor. During the rotation of the rotor, an induced current is generated in the stator coil to charge the first capacitor C1, the second capacitor C2, and the third capacitor C3. The voltage across the three capacitors lags the current by 90°. The three capacitors discharge through the stator coil to provide the excitation current, and the motor enters the power generation state.

[0103] Regarding the excitation module, the following aspects need to be explained:

[0104] I. Advantages of using capacitors for excitation

[0105] In the present invention, usually, there is residual magnetism in the rotor of the three-phase asynchronous motor. During the rotation of the rotor, an induced current is generated in the stator coil to charge the first capacitor C1, the second capacitor C2, and the third capacitor C3. The voltage across the three capacitors lags the current by 90°. The three capacitors discharge through the stator coil to provide the excitation current, and the motor enters the power generation state.

[0106] In this embodiment, by using the capacitor for excitation, automatic control of charging / discharging can be achieved, reducing other interventions and ensuring the reliable start of the elevator power generation braking intelligent device.

[0107] II. The capacitance values of the first capacitor, the second capacitor, and the third capacitor may be the same or different

[0108] In this embodiment, the capacitance values of the first capacitor, the second capacitor, and the third capacitor are the same, which can ensure that the three-phase output powers are the same in the power generation state of the three-phase asynchronous motor, thereby making the reliability of the entire circuit higher.

[0109] The present invention is not limited to this embodiment. In other embodiments of the present invention, the capacitance values of the first capacitor, the second capacitor, and the third capacitor may also be different, and can also provide excitation current for the three-phase asynchronous motor, and can also achieve the present invention, and is also within the protection scope of the present invention.

[0110] In this embodiment, capacitors are provided between the A terminal and the B terminal of the three-phase asynchronous motor; between the B terminal and the C terminal; and between the C terminal and the A terminal. However, the present invention is not limited thereto. In other embodiments of the present invention, capacitors may also be provided at only one or two of the above three positions, as long as the excitation effect can be achieved to make the three-phase asynchronous motor enter the power generation state, and it is also within the protection scope of the present invention.

[0111] III. The capacitance value formula of the first capacitor, the second capacitor, and the third capacitor

[0112] It should be noted that the above calculation of the capacitance value is only a theoretical value. In actual situations, the capacitance value needs to be adjusted according to the actual scenario and effect to achieve the best excitation effect.

[0113] In the present invention, the power load module is used to form a power load outside the three-phase asynchronous motor to consume the electric energy generated by the out-of-control three-phase asynchronous motor and generate a braking torque. Among them, the power load module includes: M impedance elements, where at least two of the three positions between the two terminals of the three-phase asynchronous motor form a power load by one or more of the M impedance elements, and M≥3.

[0114] As Figure 2 shown, the elevator power generation braking intelligent device of this embodiment further includes: a load switch group, and the load switch group includes: a first load switch K1 and a second load switch K2. The first impedance K1 and the second load switch K2 are controlled by the main control circuit, and both are relays.

[0115] The power load module includes: a first resistor R1, a second resistor R2, and a third resistor R3, where:

[0116] ① The first resistor R1 and the third resistor R3 are connected between the A terminal and the B terminal of the three-phase asynchronous motor through the first load switch K1;

[0117] ② The third resistor R3 and the second resistor R2 are connected between the B terminal and the C terminal of the three-phase asynchronous motor through the second load switch K2;

[0118] ③ The second resistor R2 and the first resistor R1 are connected between the C terminal and the A terminal of the three-phase asynchronous motor through the first load switch K1 and the second load switch K2.

[0119] Among them, the resistance values R of the first resistor, the second resistor, and the third resistor satisfy: , the unit of the resistance value R is ohm, is the rated voltage of the three-phase asynchronous motor, is the input power of the motor when the elevator is running empty.

[0120] Among them, the first load switch K1 and the second load switch K2 are relays controlled by the main control circuit. The main control circuit is also used for:

[0121] ① When detecting the out-of-control state of the elevator, set the first load switch and the second load switch to the closed state;

[0122] ② When detecting that the rotational speed of the three-phase asynchronous motor drops to a preset first rotational speed lower limit value, make at least one of the first load switch and the second load switch in the open state;

[0123] Among them, the first rotational speed lower limit value is n down-1 satisfies: n down-1 ≤ 0.8n0, where n0 is the rated rotational speed of the three-phase asynchronous motor.

[0124] In this embodiment, when the elevator power generation braking intelligent device enters the power generation state, when the magnetic encoder detects that the rotor speed is close to the rated speed, the main control electric control controls the relays K1 and K2 to close, connects the three load resistors -R1, R2, and R3, and starts to consume the electric energy output by the three-phase asynchronous motor to generate a braking torque. Further, when it is found that the rotational speed of the three-phase asynchronous motor drops to 80%, in order to avoid the collapse of the power generation state due to too low rotational speed, according to the drop of the rotational speed, choose to disconnect K1, K2 or disconnect K1 and K2 at the same time to change the load situation, adjust the braking torque, and realize continuously adjustable electric energy consumption control, so as to more accurately control the braking torque.

[0125] It should be particularly noted that in this embodiment, the free combination of R1~R3 is set, rather than calculating a fixed resistance value through the main power of the three-phase asynchronous motor, which can be explained from two aspects:

[0126] (1) Adapt to different car weights

[0127] In case of a failure, there is no way to determine how many passengers are in the car. That is to say, when there are fewer passengers in the car, the mass difference between the counterweight and the car will be larger, and then the energy generated by power generation will be more, and more energy needs to be consumed. If there are slightly more passengers in the car, it is closer to the final mass, then the mass it provides will be less, the generated electric energy will be less, and the consumed electric energy will also be less. Therefore, in this embodiment, by setting the free combination of R1~R3, it can adapt to the power consumption under different car weights and is more flexible.

[0128] (2)Avoid the breakdown of the generating state of the three-phase asynchronous motor

[0129] The present invention is to make the motor enter the asynchronous generating state, set a power load outside to consume the generated electric energy, and generate a braking resistance during the consumption process.

[0130] Regarding the reason for designing two relays and resistors, it is that the present invention needs to connect different resistors in series in the coil. Through experiments, it is found that when the actual speed of the motor is lower than 80% of the rated speed, or the power consumption reaches or exceeds 80% of the rated load of the motor, the generating state of the three-phase asynchronous motor will break down.

[0131] After the three-phase asynchronous motor breaks down in power generation, it will stop generating electricity, and the elevator will enter an out-of-control state. Therefore, it is necessary to control the load of the three-phase asynchronous motor to ensure that the output power does not exceed 80% of the rated load of the motor, and always limit the actual speed of the rotor between 80% and 110% of the rated speed. For this purpose, when the rotor speed is high, a resistor is put in to pull down the rotor speed; when the speed is low, a resistor is removed to accelerate the rotor, so that the three-phase asynchronous motor is always in the generating state until any one of the car or the counterweight reaches the buffer and the movement stops, and the rotor of the three-phase asynchronous motor also stops.

[0132] Regarding the power load module, the following aspects need to be particularly explained:

[0133] I. The resistance values of the first resistor R1, the second resistor R2, and the third resistor R3

[0134] The resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 are the same or different.

[0135] In this embodiment, the resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 are the same, which can ensure the same three-phase load, the same braking torque, and the elevator braking is more balanced and stable.

[0136] It should be particularly noted that when the resistance values of the first resistor R1, the second resistor R2, and the third resistor R3 are different, the present invention can also be realized.

[0137] II. Number of Electrical Loads

[0138] In this embodiment, when the switches of the access switch group and the load switch group are all in the closed state, there are resistors between the A terminal and the B terminal, between the B terminal and the C terminal, and between the C terminal and the A terminal of the three-phase asynchronous motor, and power consumption can be achieved in all cases, but the present invention is not limited thereto.

[0139] In some other embodiments of the present invention, resistors can be set at one or two of the three positions to achieve power consumption, which can also implement the present invention and is also within the protection scope of the present invention.

[0140] III. Access Mode of Electrical Load

[0141] In this embodiment, the adjustment of the load condition is realized through the first load switch K1 and the second load switch K2, and then the continuously adjustable power consumption control is realized, so as to more accurately control the braking torque, but the present invention is not limited thereto. In other embodiments of the present invention, the load switch may not be provided, and only by setting a load resistor between the two terminals, although the accuracy is poor, the present invention can still be implemented and is also within the protection scope of the present invention.

[0142] IV. Implementation Mode of Load Switch

[0143] In this embodiment, the first load switch K1 and the second load switch K2 are relays controlled by the main control circuit.

[0144] The present invention is not limited to this embodiment. In other embodiments of the present invention, K1 and K2 can also be replaced by other switching elements such as transistor choppers.

[0145] The applicant previously proposed an elevator and its control method (Patent Application No.: CN202311099173.9). The elevator includes: a car; a traction machine connected to the car; a drive system including a motor that drives the rotation of the traction machine through a transmission shaft; a monitoring system for monitoring the rotational speed of the transmission shaft and the AC supply current of the motor; and a speed control system that controls the drive system to reduce the rotational speed when the AC supply current is lower than a predetermined first current threshold and the rotational speed is higher than a predetermined speed threshold. Among them, the speed control system includes: a DC power supply connected in series with the motor; an insulated gate bipolar transistor IGBT connected in series with the DC power supply; and a controller that controls the DC supply current of the DC power supply when the AC supply current is lower than a predetermined first current threshold and the rotational speed is higher than a predetermined speed threshold.

[0146] Compared with the braking methods of the above-mentioned prior art, the elevator power generation braking intelligent device of this embodiment has the following advantages: ① DC braking requires continuous power supply and cannot achieve continuous braking without power supply, while power generation braking can be achieved by the self-excitation power generation of the motor, relying less on the power supply. In necessary cases, the power supply of the main control circuit can rely on the power generation of the asynchronous motor; ② DC braking requires a large braking current when braking at the rated speed or even overspeed, and such power supply may not be available in many cases. However, asynchronous power generation braking can generate braking torque with a very low power supply. After the power generation state is established, the power supply of the device itself can be supplied by the electric energy generated by the asynchronous motor, getting rid of the dependence on external power supply.

[0147] As mentioned above, there is usually residual magnetism in the rotor of a three-phase asynchronous motor, and this residual magnetism can make the motor automatically enter the asynchronous power generation state. However, in some cases, the residual magnetism in the rotor is not enough to make the motor enter the asynchronous power generation state. When the motor speed reaches 60% of the rated speed, the three-phase asynchronous motor still does not automatically enter the power generation state. At this time, an asynchronous power generation start auxiliary module is needed to excite the three-phase asynchronous motor to generate electricity.

[0148] In a typical scenario, at the moment of power-off, the rotor of the three-phase asynchronous motor just happens to be at the zero-crossing point of the three-phase alternating current, and there is no residual magnetism in the rotor, which means that the motor will not generate electricity and the three-phase asynchronous motor cannot establish an asynchronous power generation state. Or due to a long time, the residual magnetism in the rotor disappears. In these cases, the asynchronous power generation start auxiliary module in the present invention passes a pulse with a period and similar to the rotor rotation speed through a DC power supply to the three-phase asynchronous motor to magnetize the rotor. After magnetization, the three-phase asynchronous motor can enter a power generation state, ensuring the smooth start of the power generation state.

[0149] Specifically, the elevator power generation braking intelligent device of this embodiment further includes: an asynchronous power generation start auxiliary module for outputting excitation pulses to the three-phase asynchronous motor. The access switch group is connected between any two of the three-phase terminals of the asynchronous power generation start auxiliary module and the three-phase asynchronous motor. The main control circuit is used to: when it monitors that the speed of the three-phase asynchronous motor is lower than a preset second lower speed limit value, output excitation pulses to the three-phase asynchronous motor through the asynchronous power generation start auxiliary module to make the motor speed higher than the second lower speed limit value; wherein, the second lower speed limit value is between 50% and 90% of the rated speed of the three-phase asynchronous motor. In this embodiment, the second lower speed limit value is set to 70% of the rated speed of the three-phase asynchronous motor.

[0150] Please refer to Figure 2, in this embodiment, the asynchronous power generation starting auxiliary module includes: a DC power supply, whose negative output terminal is connected to the C terminal of the three-phase asynchronous motor; a switching component, whose first end is connected to the positive output terminal of the DC power supply; a diode, whose negative terminal is connected to the second end of the switching component, and whose positive terminal is connected to the A terminal of the three-phase asynchronous motor.

[0151] Preferably, in this embodiment, the output voltage of the DC power supply is between 10V and 36V. Since the impedance of the rotor coil is very low, the voltage of the asynchronous power generation starting auxiliary module is preferably lower than 36V. Preferably, the current that the asynchronous power generation starting auxiliary module can provide is 30A or 50A at 10V. In addition, the frequency of the excitation pulse f satisfies: 0.5kHz ≤ f ≤ 5kHz; the switching component is an insulated gate bipolar transistor IGBT.

[0152] Regarding the asynchronous power generation starting auxiliary module, the following aspects need to be explained:

[0153] I. The asynchronous power generation starting auxiliary module can be not provided

[0154] In this embodiment, in order to smoothly start the three-phase asynchronous motor in the power generation state, the asynchronous power generation starting auxiliary module is provided, but the present invention is not limited thereto. In some other embodiments of the present invention, the asynchronous power generation starting auxiliary module can also be not provided, and the present invention can also be realized, because the three-phase asynchronous motor may not enter the power generation state only in special cases.

[0155] II. The installation position of the asynchronous power generation starting auxiliary module

[0156] In this embodiment, the asynchronous power generation starting auxiliary module is installed between the A terminal and the C terminal of the three-phase asynchronous motor, but the present invention is not limited thereto.

[0157] In other embodiments of the present invention, the asynchronous power generation starting auxiliary module can also be installed in other positions, for example: between the B and C terminals; or, between the A and B terminals; or, the asynchronous power generation starting auxiliary module is installed at 2 or 3 of the above positions simultaneously, and the present invention can also be realized, and is also within the protection scope of the present invention.

[0158] III. The implementation method of the asynchronous power generation starting auxiliary module

[0159] In this embodiment, the excitation pulse is realized through the DC power supply and the switching component, and then the power generation starting assistance is realized, but the present invention is not limited thereto. In other embodiments of the present invention, the excitation pulse can also be directly realized by using a pulse power supply, and the present invention can also be realized, and is also within the protection scope of the present invention.

[0160] After introducing each module of this embodiment, the working conditions of this embodiment are introduced as a whole: The main control circuit detects the unexpected movement of the elevator motor through the magnetic encoder and the monitoring of the output of the voltage transmitter. When an unexpected movement is detected, the main control circuit monitors the power generation state of the three-phase asynchronous motor through the voltage transmitter. Usually, there is residual magnetism in the rotor of the motor. During the rotation of the rotor, induced current is generated in the stator coil to charge C1, C2, and C3. The voltage across the capacitor lags the current by 90°. The capacitor discharges through the stator coil to provide excitation current, and the motor enters the power generation state. If the residual magnetism of the motor rotor is not sufficient to make the motor enter the synchronous power generation state, when the motor speed reaches 70% of the rated speed, the main control circuit controls the IGBT to conduct and turn off to provide pulses slightly lower than the motor speed to two phases of the motor to assist in entering the power generation state. When the voltage transmitter monitors that the speed is close to the rated speed, it controls the relays K1 and K2 to close, connects the load resistor, and starts to consume the electric energy output by the motor to generate braking torque. When it is found that the motor speed drops to 80%, to avoid the collapse of the power generation state due to too low speed, according to the speed drop situation, K1 and K2 are selected to be disconnected or both K1 and K2 are disconnected simultaneously to change the load situation and adjust the braking torque until the elevator car or the counterweight presses on the buffer.

[0161] So far, the introduction of the elevator power generation braking intelligent device in the first embodiment of the present invention is completed.

[0162] The second embodiment of the present invention provides an elevator power generation braking intelligent device. Figure 4 It is a schematic structural diagram of the elevator power generation braking intelligent device in the second embodiment of the present invention. As Figure 4 shown, the elevator power generation braking intelligent device in this embodiment is similar to the first embodiment, the difference is that: the capacitors in the excitation module are connected in a star connection. The following focuses on the description of the excitation module.

[0163] Figure 5 For Figure 4 the schematic diagram of the star connection of the capacitors in the elevator power generation braking intelligent device shown. As Figure 4 and Figure 5 shown, in this embodiment, the excitation module includes: the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7, where: the fifth capacitor C5 and the sixth capacitor C6 are connected between the A terminal and the B terminal of the three-phase asynchronous motor; the sixth capacitor C6 and the seventh capacitor C7 are connected between the B terminal and the C terminal of the three-phase asynchronous motor; the seventh capacitor C7 and the fifth capacitor C5 are connected between the C terminal and the A terminal of the three-phase asynchronous motor; among them, the capacitance values of the fifth capacitor, the sixth capacitor, and the seventh capacitor are the same or different.

[0164] In this embodiment, the capacitance values C of the fifth capacitor, the sixth capacitor, and the seventh capacitor satisfy:[[]]END]]

[0165]

[0166] Among them, are respectively the rated current, rated voltage, and power factor of the three-phase asynchronous motor, S is a coefficient, and 500 ≤ S ≤ 3000.

[0167] Preferably, 1000 ≤ S ≤ 2000. Most preferably, 1800 ≤ S ≤ 2000.

[0168] In the setting mode of the excitation module of this embodiment, two capacitors are used to undertake the excitation work of charging and discharging. The advantages brought about are as follows: the requirement for the withstand voltage of the capacitor is relatively low, and the volume is smaller.

[0169] It can be seen from this embodiment and the first embodiment that there are various ways for the present invention to implement the excitation module through capacitors. Those skilled in the art can know how to implement these ways, and will not be elaborated here.

[0170] The third embodiment of the present invention provides an intelligent device for elevator power generation braking. Figure 6 It is a schematic structural diagram of the intelligent device for elevator power generation braking according to the third embodiment of the present invention. As Figure 6 shown, this embodiment is similar to the first embodiment, and the difference lies in the setting mode of the resistor in the power load module.

[0171] In this embodiment, the power load module includes: a full-wave rectifier circuit composed of 6 diodes; a chopper, a chopper control module, and a load resistor R4. Among them, in the power load module of the intelligent device for elevator power generation braking in this embodiment, the full-wave rectifier circuit full-wave rectifies three-phase alternating current into direct current, and the direct current is connected to the load resistor R4 through the chopper. By adjusting the chopping voltage of the chopper, the load current is continuously adjusted, so as to achieve the effect of controlling the braking torque. Among them, the switching element of the chopper is an IGBT element.

[0172] In this embodiment, the chopper is controlled by the chopper control module. When the chopper control module monitors that the DC bus voltage is higher than the set value, the chopper control module controls the IGBT to access the load resistor R4 into the circuit through pulse width modulation at a frequency of 4 kHz to 7 kHz to control the current in the load resistor. The load resistor R4 consumes electrical energy in the DC circuit to generate a braking torque. When the DC bus voltage is lower than the set value, the IGBT is turned off, and no DC circuit is formed, and the electrical energy is not consumed to prevent power generation collapse. Among them, the set value is generally set to 50% - 90% of the DC bus voltage.

[0173] The second aspect of the present invention provides an elevator. The fourth embodiment of the present invention provides an elevator. Please refer to Figure 1 and Figure 2, the elevator in this embodiment includes: a car; a traction sheave driven by a three-phase asynchronous motor; a traction rope, the middle part of which winds around the traction sheave, the first end of which is connected to the car; the second end of which is connected to a counterweight device; an elevator power generation braking intelligent device of the first embodiment; an upper buffer and a lower buffer, which are respectively arranged at the upper end and the lower end of the elevator shaft. Among them, when it is monitored that the elevator is in an out-of-control state, the three-phase asynchronous motor enters a power generation state, and the power load module serves as an output load to consume the electric energy output by the three-phase asynchronous motor, generate a braking torque, and slow down the movement speed of the elevator car.

[0174] Those skilled in the art should understand that the elevator power generation braking intelligent device in this embodiment can also adopt the elevator power generation braking intelligent devices in the second to fourth embodiments, and can also implement the present invention, and is also within the protection scope of the present invention.

[0175] So far, the various embodiments of the present invention have been introduced. Based on the above description, those skilled in the art should have a clear understanding of the present invention.

[0176] It should be noted that unless clearly specified to the contrary, the numerical parameters in the specification and claims of the present invention can be approximate values and can be changed according to the content of the present invention. Specifically, all the numbers representing the content of the composition, reaction conditions, etc. recorded in the specification and claims should be understood to be modified by the term "about" in all cases, and the meaning expressed is that it includes a change of ±10% of a specific quantity in some embodiments.

[0177] The ordinal numbers such as "first", "second", "third", "main", "sub", as well as Arabic numerals, letters, etc. used in the specification and claims are used to modify the corresponding elements (or steps). Their original intention is only to enable an element (or step) with a certain name to be clearly distinguished from another element (or step) with the same name, and does not mean that the element (or step) has any ordinal number, nor does it represent the order of one element (or step) and another element (or step).

[0178] The present invention can also be implemented as a device or device program (such as a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present invention can be stored on a computer-readable medium, or can have the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0179] The present invention can be implemented by means of hardware including several different components and by means of a properly programmed computer. Each component embodiment of the present invention can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Physical implementations of the hardware structure include, but are not limited to, physical devices, which include, but are not limited to, transistors, memristors, DNA computers, single-chip microcomputers, microprocessors, or digital signal processors (DSPs). In addition, the present invention is not directed to any specific programming language. It should be understood that the content of the present invention can be implemented using various programming languages, and the description of a specific language herein is for the purpose of disclosing the best mode of the present invention.

[0180] Those skilled in the art should understand that in the claims and the specification of the present invention, the word "comprising" does not exclude the presence of elements not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. For some implementations, if they are not the key content of the present invention and are well known to those of ordinary skill in the art, they are not described in detail in the accompanying drawings or the text of the specification due to space limitations, and in this case, reference may be made to the relevant prior art for understanding.

[0181] Moreover, the purpose of providing the above embodiments is only to make the present invention meet legal requirements, and the present invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0182] Similarly, it should be understood that, for the purpose of streamlining the present invention, in the above description of the exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be construed as reflecting the intention that the claimed invention requires more features than those expressly recited in each claim. Rather, as reflected in the claims, each inventive aspect lies in less than all the features of the preceding single embodiment. Moreover, the embodiments can be combined with each other based on design and reliability considerations, or combined with other embodiments, that is, the technical features in different embodiments can be freely combined to form more embodiments. Therefore, the claims following the specific embodiments are hereby expressly incorporated into the specific embodiments, where each claim itself serves as a separate embodiment of the present invention.

[0183] In the above specific embodiments, the purpose, technical means, and beneficial effects of the present invention are described in detail. It should be understood that the purpose of the detailed description is for those skilled in the art to understand the present invention more clearly and is not used to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An intelligent device for elevator power generation braking, characterized in that, Comprising: An excitation module and a power load module; A status monitoring module for monitoring the operating status of the elevator; An access switch group connected between the excitation module, the power load module and the three-phase terminals of the three-phase asynchronous motor; A main control circuit for controlling the access switch group to connect the excitation module and the power load module to the three-phase asynchronous motor when an out-of-control state of the elevator is detected, wherein: The excitation module provides excitation current for the three-phase asynchronous motor; The rotor of the three-phase asynchronous motor rotates due to the out-of-control of the elevator, and the three-phase asynchronous motor enters a power generation state and outputs electric energy outward; The power load module consumes the electric energy, thereby generating a braking torque on the out-of-control elevator A load switch group, including: a first load switch, a second load switch; An asynchronous power generation start auxiliary module for outputting excitation pulses to the three-phase asynchronous motor; wherein, the access switch group is connected between any two of the three-phase terminals of the asynchronous power generation start auxiliary module and the three-phase asynchronous motor; Wherein, the power load module includes: a first resistor, a second resistor, a third resistor, wherein: the first resistor and the third resistor are connected between the A terminal and the B terminal of the three-phase asynchronous motor through the first load switch; the third resistor and the second resistor are connected between the B terminal and the C terminal of the three-phase asynchronous motor through the second load switch; the second resistor and the first resistor are connected between the C terminal and the A terminal of the three-phase asynchronous motor through the first load switch and the second load switch; Wherein, the main control circuit is further used for: When detecting the out-of-control state of the elevator, setting the first load switch and the second load switch to the closed state; When detecting that the rotational speed of the three-phase asynchronous motor drops to a preset first rotational speed lower limit value, making at least one of the first load switch and the second load switch in an open state; Among them, the lower limit value of the first rotational speed is n down-1 satisfies: n down-1 ≤0.8n0, where n0 is the rated rotational speed of the three-phase asynchronous motor; Wherein, the actual rotational speed of the three-phase asynchronous motor is limited between 80% and 110% of the rated rotational speed. When the actual rotational speed is higher than the above range, the resistor is inserted. When the actual rotational speed is lower than the above range, the resistor is withdrawn until any one of the car or the counterweight reaches the buffer and the movement stops; Wherein, the main control circuit is further used for: When detecting that the rotational speed of the three-phase asynchronous motor is higher than a preset second rotational speed lower limit value, if no output voltage of the three-phase asynchronous motor is detected, the main control circuit outputs excitation pulses to the three-phase asynchronous motor through the asynchronous power generation start auxiliary module to make the motor enter the asynchronous power generation state; Wherein, the second rotational speed lower limit value is between 50% and 90% of the rated rotational speed of the three-phase asynchronous motor.

2. The intelligent elevator power generation braking device according to claim 1, wherein, The excitation module includes: N capacitors, N≥2; Wherein, an energy storage and energy release excitation unit is formed by one or more of the N capacitors between the two ends of the three-phase terminals of the three-phase asynchronous motor.

3. The intelligent elevator power generation braking device according to claim 2, characterized in that, The excitation module includes: a first capacitor, a second capacitor, a third capacitor, wherein: The first capacitor is connected between the A terminal and the B terminal of the three-phase asynchronous motor; The second capacitor is connected between the B terminal and the C terminal of the three-phase asynchronous motor; The third capacitor is connected between the A terminal and the C terminal of the three-phase asynchronous motor; Among them, the capacitance values of the first capacitor, the second capacitor, and the third capacitor are the same or different.

4. The intelligent elevator power generation braking device according to claim 3, wherein The three-phase asynchronous motor is a power frequency motor, and the capacitance values C of the first capacitor, the second capacitor, and the third capacitor satisfy: wherein, the unit of the capacitance value C is μF, I n , U n , Cosφ n are respectively the rated current, the rated voltage, and the power factor of the three-phase asynchronous motor, K is a coefficient, and 500 ≤ K ≤ 10000; or The three-phase asynchronous motor is a non-power frequency motor, and the capacitance values C of the first capacitor, the second capacitor, and the third capacitor satisfy: where: the unit of the capacitance value C is μF, I n , U n , f are respectively the rated current, rated voltage, and rated frequency of the three-phase asynchronous motor, and Q is a coefficient, 0.1 ≤ Q ≤ 1.

5. The intelligent elevator power generation braking device according to claim 4, wherein The withstand voltages of the first capacitor, the second capacitor, and the third capacitor are not less than 110% of the rated voltage of the three-phase asynchronous motor; And / or, the three-phase asynchronous motor is a power frequency motor with a working frequency of 50 Hz, and the capacitance values C of the first capacitor, the second capacitor, and the third capacitor are the same, 3000 ≤ K ≤ 3500; or, the three-phase asynchronous motor is a non-power frequency motor, and the capacitance values C of the first capacitor, the second capacitor, and the third capacitor are the same, 0.2 ≤ Q ≤ 0.

4.

6. The intelligent elevator power generation braking device according to claim 2, wherein The excitation module includes: a fifth capacitor, a sixth capacitor, and a seventh capacitor, wherein: The fifth capacitor and the sixth capacitor are connected between the A terminal and the B terminal of the three-phase asynchronous motor; The sixth capacitor and the seventh capacitor are connected between the B terminal and the C terminal of the three-phase asynchronous motor; The seventh capacitor and the fifth capacitor are connected between the C terminal and the A terminal of the three-phase asynchronous motor; Among them, the capacitance values of the fifth capacitor, the sixth capacitor, and the seventh capacitor are the same or different.

7. The intelligent elevator power generation braking device according to claim 6, wherein, The capacitance values C of the fifth capacitor, the sixth capacitor, and the seventh capacitor satisfy: Among them, I n , U n , Cosφ n are respectively the rated current, rated voltage, and power factor of the three-phase asynchronous motor, S is a coefficient, and 500 ≤ S ≤ 3000.

8. The intelligent elevator power generation braking device according to claim 1, wherein The first load switch and the second load switch are: a relay or a transistor chopper; And / or, the resistance values of the first resistor, the second resistor, and the third resistor are the same or different; And / or, the resistance values R of the first resistor, the second resistor, and the third resistor satisfy: Among them, the unit of the resistance value R is ohm, and U n is the rated voltage of the three-phase asynchronous motor, and P n is the input power of the motor when the elevator is running without load, and 0.5 ≤ T ≤ 2.

9. The intelligent elevator power generation braking device according to claim 8, wherein The resistance values of the first resistor, the second resistor, and the third resistor are the same; The resistance values R of the first resistor, the second resistor, and the third resistor satisfy:

10. The intelligent elevator power generation braking device according to claim 1, characterized in that, The asynchronous power generation starting auxiliary module includes: A DC power supply, whose negative output terminal is connected to one of the three terminals of the three-phase asynchronous motor; A switch component, whose first end is connected to the positive output terminal of the DC power supply, and whose second end is connected to another one of the three terminals of the three-phase asynchronous motor.

11. The intelligent elevator power generation braking device according to claim 10, wherein The asynchronous power generation starting auxiliary module further includes: a diode, whose negative terminal is connected to the second end of the switch component, and whose positive terminal is connected to another one of the three terminals of the three-phase asynchronous motor; And / or, the frequency f of the excitation pulse satisfies: 0.5 kHz ≤ f ≤ 5 kHz; And / or, the output voltage of the DC power supply is between 10V and 36V; And / or, the switch component is an insulated gate bipolar transistor IGBT.

12. The intelligent elevator power generation braking device according to claim 1, wherein The state monitoring module is used to monitor the active power input and the rotor rotation in the elevator; The main control circuit is used to determine that the elevator is in an out-of-control state when the following conditions are met: the three-phase asynchronous motor rotates without active power input; and execute the following control logic according to the determination result: When the out-of-control state of the elevator is not detected, keep the connection terminals of both the excitation module and the power load module connected to the three-phase asynchronous motor and the elevator control cabinet isolated; When the out-of-control state of the elevator is detected, control the access switch group to connect both the excitation module and the power load module in parallel to the connection terminals between the three-phase asynchronous motor and the elevator control cabinet.

13. The intelligent elevator power generation braking device according to claim 12, characterized in that, The state monitoring module includes: A motor power monitoring module, which is used to monitor the power voltage input to the three-phase asynchronous motor; A motor rotation monitoring module, which is used to monitor the rotation of the rotor in the three-phase asynchronous motor.

14. The intelligent elevator power generation braking device according to claim 13, wherein The motor rotation monitoring module is: a magnetic encoder, which is arranged at the shaft end of the three-phase asynchronous motor, and the shaft end is connected to the rotor, and its sampling period T satisfies: T≤20ms.

15. A traction drive elevator, characterized in that, It includes: A car; A traction wheel, which is driven by a three-phase asynchronous motor; A traction rope, the middle part of which passes around the traction wheel, the first end is connected to the car; the second end is connected to the counterweight device; The intelligent elevator power generation braking device according to any one of claims 1 to 14; An upper buffer and a lower buffer, which are respectively arranged at the upper end and the lower end of the elevator shaft; Wherein, when it is detected that the elevator is in an out-of-control state, the three-phase asynchronous motor enters the power generation state, and the power load module is used as the output load to consume the electric energy output by the three-phase asynchronous motor, generate a braking torque, and slow down the movement speed of the elevator car.

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